1. Field of the Invention
The present invention relates generally to dental implants and, more particularly, to a dental implant delivery system.
2. Description of the Related Art
Dental implants are placed in the jaw to provide support for a dental restoration, fixed bridge or removable partial denture. Dental implants provide good chewing function and also improve the patient's cosmetic appearance thereby allowing the patient to smile, speak, and interact with others with greater confidence.
One type of dental implant widely used in the industry is typically referred to as a “threaded” implant. Threaded implants have an externally threaded body portion which is screwed into a pre-drilled hole (i.e. an osteotomy) in the patient's upper or lower jawbone. Typically, the threaded implant body is formed with a central threaded socket accessible through the overlying gum tissue for receiving and supporting one or more dental attachments or components. Types of attachments and components that are received by the central socket include healing caps, impression copings and abutments. In turn, some of these attachments and components are useful to fabricate and/or support the prosthodontic restoration.
Dental implants are typically packaged as an assembly including all the tools necessary for the insertion of the implant into an osteotomy formed in the jaw. A typical threaded implant assembly includes a threaded implant body, an implant carrier, an insertion post, a coupling screw and a healing cap. Conventionally, these components are sterilized, pre-assembled and packaged in a sterile vial. The implant carrier, insertion post, and coupling screw are tools which are used during the insertion of the implant body. Typically, the implant carrier, insertion post, coupling screw and vial are discarded after the implant body has been inserted into the osteotomy. The healing cap seals and protects the central socket of the implant body during the initial healing period, and then is discarded.
During the insertion of a conventional threaded implant, the insertion post is mechanically coupled to the top of the implant body by a coupling screw which traverses a central through-cavity in the insertion post and is threaded into the central threaded socket in the implant body. Typically, the bottom end of the insertion post is formed with a hexagonal cavity that irrotationally mates with a corresponding hexagonal protrusion formed on the top of the implant body thereby preventing any relative rotation between the insertion post and implant body while coupled.
An implant carrier is releasably coupled to the top of the insertion post and provides the dental practitioner with a means to grip and manipulate the assembly during the initial implantation procedure. Typically, the implant carrier is formed with a generally hexagonal internal passage at its bottom end which mates with a generally hexagonal outer surface near the top of the insertion post. The dental practitioner uses the implant carrier to manipulate the implant body into the proper location within the jawbone. Torque is applied to the implant carrier which is transferred, via the insertion post, to the threaded implant body.
In use, the first step of a typical implantation procedure involves making an incision in the patient's gum tissue. A portion of the gum tissue is then folded back and an osteotomy is drilled in the jawbone. The diameter of the osteotomy is equal to or slightly smaller than the diameter of the implant body. The implant carrier is then used to transport the threaded implant assembly to the surgical site. The implant carrier is gripped by the practitioner and is used to manipulate the implant body into the correct position and then to partially screw the threaded implant body into the osteotomy.
Once the implant body has been initially placed in the osteotomy and tightened manually, the implant carrier is decoupled from the insertion post and is removed from the surgical site. If necessary, a suitable wrench or dental hand piece is then used to engage the insertion post and drive the implant to its final depth within the osteotomy. The coupling screw is then removed and the insertion post is decoupled from the implant body leaving only the implant body in the patient's mouth.
The healing cap is housed in a cavity formed in the top of the implant carrier where it is contained by a paper barrier until needed. At this point, the healing cap is removed from the implant carrier and is threaded into the central socket of the implant body. Typically, a tool with a hexagonal tip is inserted into a corresponding mating hexagonal recess located in the top center of the healing cap and is used to apply torque to tighten the healing cap. The healing cap protects the implant socket against bone or tissue ingrowth during the initial healing period, and also prevents the entry of bacteria or other contaminants into the central socket of the implant body.
The insertion of the implant body and healing cap is then followed by an initial healing period in which the bone is allowed to surround and retain the implant (i.e. “osseointegrate” with the implant) and the gum tissue is allowed to heal over the implant body and healing cap. For implants placed in the mandible, healing typically requires about three months; for implants in the maxilla, the healing period typically requires about six months.
After the implant body has sufficiently osseointegrated with the jawbone, the gum tissue is re-opened by making an incision and the gum tissue is folded back to expose the healing cap. A hexagonal tool is inserted into the recess in the top of the healing cap and torque is applied to rotate the healing cap out of the implant socket and to remove it from the implant body. During this step of the procedure, great care must be used to remove the healing cap without disturbing the position of the implant body. Any disturbance of the implant body during the removal of the healing cap could damage the osseointegration between the implant body and the jawbone. Damage to the osseointegration is very undesirable and could endanger the entire restoration process by destabilizing the implant. In addition, any movement of the implant body could result in gaps or spaces between the implant body and jawbone which could in turn lead to infection by bacteria and/or other contaminants.
After the healing cap has been unscrewed and removed from the patient's mouth, a suitable healing abutment is inserted into the central socket. The healing abutment extends through the gum tissue overlying the implant site. A second healing period then ensues in which the gum tissue is allowed to heal around the post-osseointegration healing abutment. Typically, this second healing period lasts from four to eight weeks.
After the second healing period has ended, the healing abutment is removed from the implant body. Typically, an impression is taken of the patient's mouth to fabricate a prosthesis or dental restoration. An abutment supporting the final restoration is then attached to the implant body. Lastly, the restoration is cemented or screwed to the abutment and/or implant body to complete the placement of the prosthodontic restoration in the patient's mouth.